Heap-based buffer overflow in Microsoft Office - CVE-2026-70291
Published: October 14, 2026
Vulnerability identifier: #VU154712
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-70291
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to heap-based buffer overflow in Microsoft Office Outlook when rendering email messages in the Reading Pane. A remote attacker can send a specially crafted email message to a target user to execute arbitrary code.
The Preview Pane is an attack vector. Exploitation does not require the recipient to open the message or click its contents, and no user interaction is required.
Affected software
Microsoft Office
How to mitigate CVE-2026-70291
Install security update from vendor's website.
Microsoft Office - addressed in versions 16.0.14334.20974, 16.0.17932.21056